U.S. patent application number 11/284765 was filed with the patent office on 2007-05-24 for electronic thermometer with progress indicator.
This patent application is currently assigned to Sherwood Services AG. Invention is credited to Michael E. Bisch, Joseph T. Gierer.
Application Number | 20070116089 11/284765 |
Document ID | / |
Family ID | 37719291 |
Filed Date | 2007-05-24 |
United States Patent
Application |
20070116089 |
Kind Code |
A1 |
Bisch; Michael E. ; et
al. |
May 24, 2007 |
Electronic thermometer with progress indicator
Abstract
An electronic thermometer with a progress indicator. A control
circuit of the thermometer performs at least one temperature
calculation as a function of a detected temperature and generates a
temperature signal representative of the temperature of a subject
based on the temperature calculation. A progress indicator visually
indicates progress of the control circuit in performing the
temperature calculation.
Inventors: |
Bisch; Michael E.;
(Kirkwood, MO) ; Gierer; Joseph T.; (Glen Carbon,
IL) |
Correspondence
Address: |
TYCO HEALTHCARE - EDWARD S. JARMOLOWICZ
15 HAMPSHIRE STREET
MANSFIELD
MA
02048
US
|
Assignee: |
Sherwood Services AG
Schaffhausen
CH
|
Family ID: |
37719291 |
Appl. No.: |
11/284765 |
Filed: |
November 22, 2005 |
Current U.S.
Class: |
374/208 ;
374/163; 374/E13.002; 374/E7.042 |
Current CPC
Class: |
G01K 7/42 20130101; G01K
13/20 20210101 |
Class at
Publication: |
374/208 ;
374/163 |
International
Class: |
G01K 7/00 20060101
G01K007/00; G01K 1/00 20060101 G01K001/00 |
Claims
1. An electronic thermometer comprising: a probe adapted to be
heated by a subject for use in measuring the temperature of the
subject; at least one temperature sensor for detecting the
temperature of the probe; a control circuit responsive to the
temperature sensor for performing at least one temperature
calculation as a function of the detected temperature of the probe
and generating a temperature signal representative of the
temperature of the subject based on the temperature calculation;
and a progress indicator for visually indicating progress of the
control circuit in performing the temperature calculation.
2. The electronic thermometer of claim 1, further comprising a
screen on which the progress indicator is displayed.
3. The electronic thermometer of claim 2, wherein the progress
indicator comprises a graphical user interface component
representative of a progress bar displayed on the screen.
4. The electronic thermometer of claim 2, wherein the progress
indicator comprises a graphical user interface component
representative of a pie chart displayed on the screen.
5. The electronic thermometer of claim 1, wherein the progress
indicator comprises a progress bar having a variable length
indicative of a percentage of completion of the control circuit in
performing the temperature calculation.
6. The electronic thermometer of claim 5, wherein the progress bar
is oriented substantially vertically relative to a longitudinal
axis of the thermometer.
7. The electronic thermometer of claim 5, wherein the progress bar
is oriented substantially horizontally relative to a longitudinal
axis of the thermometer.
8. The electronic thermometer of claim 1, wherein the progress
indicator comprises a plurality of segments, each of said segments
having a visual characteristic for representing a percentage of
completion of the control circuit in performing the temperature
calculation.
9. The electronic thermometer of claim 8, wherein the progress
indicator comprises a segmented bar.
10. The electronic thermometer of claim 8, wherein the progress
indicator comprises a pie icon having a plurality of pie-shaped
segments.
11. The electronic thermometer of claim 1, wherein the progress
indicator comprises a visual characteristic representative of an
error condition.
12. The electronic thermometer of claim 1, wherein the progress
indicator comprises a visual characteristic representative of a
reset condition.
13. The electronic thermometer of claim 1, wherein the control
circuit comprises a temperature prediction component configured to
calculate a predicted temperature of the subject using an optimized
temperature prediction algorithm.
14-28. (canceled)
Description
BACKGROUND
[0001] The healthcare field widely uses electronic thermometers for
measuring a patient's body temperature. A typical electronic
thermometer has a thermistor or other temperature sensitive element
contained within an elongated shaft portion of a probe. In one
version, the probe includes a cup-shaped aluminum tip at its free
end. A thermistor is placed in thermal contact with the aluminum
tip inside the probe. When the free end of the probe is placed in,
for example, a patient's mouth (or rectum or axilla), the tip heats
up and the thermistor measures the temperature of the tip to obtain
a measurement of the patient's body temperature. Additional
electronics connected to these electronic sensor components may be
contained within a base unit connected by wire to the shaft portion
or may be contained within a handle of the shaft portion.
Electronic components receive input from the sensor components to
compute the patient's temperature. The thermometer typically
displays the patient's temperature on a visual output device, such
as a seven segment numerical display device. Additional features of
known electronic thermometers include an audible temperature level
notification (e.g., a beep or tone alert signal). A disposable
cover or sheath is often fitted over the shaft portion and disposed
of after each use of the thermometer for sanitary reasons.
[0002] Electronic thermometers have many advantages over
conventional thermometers and have essentially replaced the use of
conventional glass thermometers in the healthcare field. One
advantage of electronic thermometers over their conventional glass
counterparts is the speed at which a temperature reading can be
taken. Several procedures are used to promote a rapid measurement
of the subject temperature. One technique employed is to use
predictive algorithms as part of thermometer logic to extrapolate
the temperature measurement from the thermistor in contact with the
tip, to arrive at a temperature reading in advance of the tip
reaching equilibrium with the body temperature. Another technique
that can be employed simultaneously with a predictive algorithm is
to heat the probe to near the body temperature, so that the portion
of the probe away from the tip does not act as a heat sink. This
allows the tip to reach a temperature close to the body temperature
more rapidly. Heating with the probe can be accomplished by a
resistor placed in contact with the probe. Another thermistor may
be placed in contact with the probe to measure the amount of heat
provided by the resistor for controlling the heating. It is also
known to use an isolator to reduce heat loss from the tip to other
parts of the probe. For example, commonly assigned U.S. Pat. No.
6,839,651, the entire disclosure of which is incorporated herein by
reference, discloses a prediction type electronic thermometer
having an actively controlled heater element thermally isolating
the probe tip from the probe shaft.
[0003] Although most predictive thermometers provide an activity
indication during a prediction measurement to indicate that
measurement and prediction activity are occurring, there is no way
for a user to know how far along the process has progressed.
Further, the thermometer can experience interruptions in the
data/temperature trend that cause the algorithm to restart, and for
which there is no indication. For example, if the probe is moved
within the patient's mouth to a region having a different
temperature (e.g., from under the tongue to not under it), the
algorithm must restart. Conventional electronic thermometers
provide no way for the user to know when anything has interrupted
the prediction process.
SUMMARY
[0004] Embodiments of the invention overcome one or more
deficiencies in known systems by providing a progress indicator
that will visually represent, in real time, how close an electronic
thermometer is to producing a temperature reading. For predictive
thermometers, aspects of the invention provide an indication of how
close the prediction is to completion. In addition, one embodiment
of the invention provides visual feedback if the thermometer must
restart or reset for some reason. Moreover, the features of the
present invention described herein are user friendly and intuitive
as well as being economically feasible and commercially
practical.
[0005] Briefly described, an electronic thermometer embodying
aspects of the invention has a probe adapted to be heated by a
subject for use in measuring the temperature of the subject and at
least one temperature sensor for detecting the temperature of the
probe during operation. A control circuit responsive to the
temperature sensor performs at least one temperature calculation as
a function of the detected temperature of the probe and generates a
temperature signal representative of the temperature of the subject
based on the temperature calculation. In addition, the thermometer
includes a progress indicator for visually indicating progress of
the control circuit in performing the temperature calculation.
[0006] According to another aspect of the invention, a method of
indicating status of an electronic thermometer includes performing
at least one temperature calculation as a function of a detected
temperature of a probe, which is adapted to be heated by a subject
for use in measuring the temperature of the subject. The method
also includes defining a plurality of states, each of which
corresponds to an amount of completion of the temperature
calculation. The method further includes visually indicating
progress of the temperature calculation based on the defined
states.
[0007] Yet another aspect of the invention is directed to a medical
device that has a control circuit configured to perform at least
one operation over time and a progress indicator for visually
indicating progress of the control circuit in performing the
operation.
[0008] Other features will be in part apparent and in part pointed
out hereinafter.
[0009] This Summary is provided to introduce a selection of
concepts in a simplified form that are further described below in
the Detailed Description. This Summary is not intended to identify
key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of
the claimed subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective of an electronic thermometer
according to embodiments of the invention.
[0011] FIG. 2 is an exemplary progress indicator according to an
embodiment of the invention.
[0012] FIG. 3 is an exemplary progress indicator according to
another embodiment of the invention.
[0013] FIG. 4 is an exemplary flow diagram illustrating a progress
determination of a temperature prediction process according to an
embodiment of the invention.
[0014] FIG. 5 and FIG. 6 are exemplary flow diagrams illustrating a
stability variance determination of a temperature prediction
process according to another embodiment of the invention.
[0015] Corresponding reference characters indicate corresponding
parts throughout the drawings.
DETAILED DESCRIPTION
[0016] Referring now to the drawings and in particular to FIG. 1,
an electronic thermometer constructed according to the principles
of the present invention is indicated generally at 11. The
electronic thermometer comprises a temperature control circuit or
unit, indicated generally at 13, that is sized and shaped to be
held comfortably in the hand H. The control unit 13 (broadly, "a
base unit") is connected by a helical cord 15 to a probe 17 (the
reference numerals indicating their subjects generally). The probe
17 is constructed for contacting the subject (e.g., a patient) and
sending signals to the control unit 13 representative of the
temperature. The control unit 13 receives the signals from probe 17
and uses them to calculate the temperature. Suitable circuitry for
performing these calculations is contained within a housing 19 of
the control unit 13. The logic in the circuitry may include a
predictive algorithm for rapidly ascertaining a final temperature
of the patient. The circuitry makes the calculated temperature
appear on a LCD display 21 on the front of the housing 19. Other
information desirably can appear on the display 21, as will be
appreciated by those of ordinary skill in the art. A panel 21A of
buttons for operating the thermometer 11 is located just above the
display 21. In the embodiment of FIG. 1, display 21 includes a
progress indicator 23.
[0017] Those skilled in the art are familiar with various user
interfaces for displaying information to a user and receiving user
input. As an example, display 21 may be a graphical user interface
having a touch screen by which the user can provide input. In this
example, the panel 21A could be embodied on display 21 itself.
[0018] The housing 19 includes a compartment (not shown) generally
at the rear of the housing that can receive a distal portion of the
probe 17 into the housing for holding the probe and isolating the
distal portion from the environment when not in use. FIG. 1
illustrates probe 17 being pulled by the other hand H1 from the
compartment in preparation for use. The housing 19 also has a
receptacle 25 that receives a suitable container such as a carton C
of probe covers (not shown). In use, the top of the carton C is
removed, exposing open ends of the probe covers. The distal portion
of probe 17 can be inserted into the open end of the carton C and
one of the probe covers can be captured (e.g., snapped into) an
annular recess. The probe 17 may be protected from contamination by
the cover when a user inserts the distal portion of a probe shaft
35 into, for example, a patient's mouth. When depressed, a button
37 on the probe handle 33 causes pushers located at the junction of
the probe shaft 35 and a handle 33 of probe 17 to move for
releasing the probe cover from probe shaft 35. Subsequent to use,
the probe cover is discarded. Other ways of capturing and releasing
probe covers may be used without departing from the scope of the
present invention.
[0019] An aluminum tip at the distal end of probe shaft 35 is
heated up by the patient and the temperature of the tip is
detected, as will be described more fully hereinafter. The probe
cover is preferably made of highly thermally conductive material,
at least at the portion covering the tip, so that the tip can be
rapidly heated by the patient. Batteries (not shown) may be used to
power a tip thermistor (not shown), separator thermistor (not
shown), and/or resistor (not shown) preferably located in the
housing 19 of thermometer 11. It will be understood that other
suitable power sources could be employed. The power source need not
be located in the control unit housing 19. In general, the tip
thermistor generates a signal that is representative of the
temperature of the tip. The signal is transmitted by one or more
electrical conductors to the circuitry in housing 19. As described
above, the resistor is powered by the batteries and heats a
separator (not shown) so that the aluminum tip can reach the
temperature of the patient more rapidly. Monitoring the temperature
of the separator with the separator thermistor allows the heating
of the resistor to be controlled to achieve optimum results. For
instance, the separator can be initially rapidly heated, but then
heated intermittently as the separator nears or reaches a
preselected temperature. The function and operation of these
components are known to those of ordinary skill in the art. It will
be appreciated that various electrical components (not shown) and
other arrangements and numbers of components may be used without
departing from the scope of the present invention.
[0020] For example, commonly assigned U.S. Pat. No. 6,634,789, U.S.
Pat. No. 6,839,651, and U.S. patent application Ser. No.
11/266,548, and U.S. patent application Ser. No. 11/265,984, the
entire disclosures of which are incorporated herein by reference,
disclose electronic thermometers.
[0021] The response time of electronic thermometers has also been
improved by methods that do not involve heating the probe shaft or
tip. Predictive type thermometers are known, for example, wherein a
set of early temperature measurements are read by the electronics
of the thermometer and a mathematical algorithm is applied to
extrapolate to a final estimated equilibrium temperature. Various
prediction type thermometers are known that improve response time
and provide accurate temperature estimations. Still other methods
of improving the response time of electronic thermometers are known
which combine heating methods with prediction methods. Using
predictive techniques, the patient's temperature reading is taken
in a significantly shorter time period, for example thirty seconds,
compared to several minutes required for conventional Mercury
thermometers.
[0022] Predictive thermometers use a numerical algorithm to
accelerate the speed with which a patient's body temperature is
acquired. The algorithm uses the temperature history of the
thermometer's probe and projects where the final temperature
reading will be. In order for the software to be satisfied that an
accurate temperature has been predicted, a certain number of final
temperature projections must fall within a certain range or
tolerance of each other.
[0023] Despite the response time improvements over glass
thermometers, typical electronic thermometers can still have
unacceptably long response times. Delay in providing a temperature
reading often results from the patient inadvertently repositioning
probe 17 during the measurement. For example, if the patient moves
the probe to a region having a different temperature (e.g., from
under the tongue to not under it) the algorithm may need to
restart. This may also be the case if the patient draws in a breath
of air over the probe. As described above, conventional predictive
thermometers at most provide an activity indication during a
prediction measurement to indicate that measurement and prediction
activity are occurring. But there is no way for a user of a
conventional thermometer to know how far along the process has
progressed. Further, if the thermometer experiences interruptions
in the data/temperature trend that cause the algorithm to restart,
there is no indication by a conventional thermometer. Thus, users
desire progress information.
[0024] According to aspects of the invention, the progress
indicator 23 provides a user friendly, visual indication of
relative completion of the prediction. As shown in the examples of
FIGS. 2 and 3, progress indicator 23 may take the form of any type
of visual indication or display, such as a progress bar (oriented
horizontally or vertically on the display screen 21) (see FIG. 2)
or a pie graph (see FIG. 3). For example, indicator 23 may be a
series of icons or segments 41 forming a bar, a segmented single
bar, a continuous bar that is progressively filled in or
illuminated, or a continuous bar of variable length, all within the
scope of the present invention. In these exemplary embodiments,
indicator 23 essentially takes the form of a variable length bar
that provides a visual characteristic for indicating a relative
amount of completion of the temperature calculations. In an
alternative embodiment, indicator 23 may be a pie graph or "pin
wheel" having pieces 43 that are progressively filled in
piece-by-piece as thermometer 11 performs the temperature
calculations. Similarly to a bar-type indicator, the pie graph may
also be filled in progressively in a continuous manner. Those
skilled in the art are familiar with generating graphical user
interface components for displaying symbols such as those
contemplated herein on an LCD screen or other type of display in
color, gray scale, or monochrome.
[0025] In one embodiment, display 21 displays the temperature as
estimated during the operation of progress indicator 23. This
temperature may be updated as progress continues. In the
alternative, thermometer 11 waits until completion of the
temperature calculations to display the temperature reading.
[0026] Referring now to the exemplary embodiment of FIG. 2,
indicator 23, in the form of a variable length or segmented bar,
"marches" along as the sequence of ongoing predictions start to
converge to an answer (i.e., the trend flattens out and becomes
more consistent). As shown in FIG. 2(a), progress indicator 23 has
a single segment 41 filled in, which indicates that the temperature
calculations are just beginning. It is to be understood that each
segment 41 may be embodied by an LED, a shaded or colored icon or
portion of the bar, a bright or illuminated icon or portion of the
bar, a blinking or solid icon or portion of the bar, or the like to
visually distinguish itself from the remainder of the bar.
Moreover, segments 41 may abut each other or be separated and may
be grouped or boxed to indicate the full length of the bar. FIG.
2(b) illustrate that thermometer 11 has completed about half of the
necessary calculations for rendering a final temperature. FIG. 2(c)
illustrates that an interruption to the temperature calculations
may have occurred, resulting in a fall back in progress. In other
words, if the trend is interrupted for any reason and the
prediction must restart, progress indicator 23 provides such an
indication by becoming less filled in and resets as appropriate.
Conversely, an immediate full bar may be used to indicate an error
(e.g., bad placement). At FIG. 2(d), only the last segment 41
remains to indicate the thermometer 11 is nearing completion of its
temperature calculations. In this embodiment, segment 41A may be
blinking or otherwise visually distinguishable from the other
filled in segments 41 to indicate the current relative status of
completion.
[0027] As shown in the exemplary flow diagram of FIG. 4, in one
embodiment of the invention, control unit 13 continuously samples
the temperature thermistor at 47 during a prediction determination
and generates progress indicator 23 as a function of the patient
thermistor. Using a software loop, control unit 13 saves and
compares the last several samples at 49 for determining the trend
toward a final temperature measurement. In other words, variables
can be used to see if consecutive thermistor readings are getting
closer together. For example, control unit 13 uses the following at
51: PatientCountLast=PatientCountNow
PatientCountNow=ThermistorValueNow PatientDiff3=PatientDiff2
PatientDiff2=PatientDiff1
PatientDiff1=PatientCountNow-PatientCountLast
PatientDiffAve=(PatientDiff3+PatientDiff2+PatientDiff1)/3
[0028] The value PatientDiffAve in this example is the average of
the last three sets of differences accumulated.
[0029] As described above, progress indicator 23 may be any number
of discrete pieces and may take many different shapes or
appearances. The bar shown in FIG. 2 provides a suitable
implementation of progress indicator 23 because users are familiar
with the use of a bar in the context of many computer applications
to indicate "busy" or "activity." For this example, seven segments
41 are used to define a complete bar. The various states of
completion of progress indicator 23 are numbered 0-6 in this
example where the state number represents the number of pieces or
segments 41 that are "on" during that state. For example, in state
0 there are no segments turned on; in state 1 there is one segment
turned on; and so forth. Thus, a progress bar begins at state 0 and
sequentially progresses to state 1, 2, 3, 4, 5, and 6. At state 6,
a complete bar indicates that the activity is substantially 100%
complete. In one embodiment, the states are defined as a function
of temperature, time, etc.
[0030] According to aspects of the invention, there may be many
ways to determine when and how the states progress from 0 to 6. For
example, if an activity is expected to take a relatively consistent
amount of time, the states might progress based on a time interval
(with the final state being slightly delayed until the activity is
complete). In an alternative embodiment, state progression may be
defined according to the PatientDiffAve value described above.
Referring again to FIG. 4, exemplary states are defined at 53 as
follows: if (PatientDiffAve*2.gtoreq.200) then State=0 if
(PatientDiffAve*2.gtoreq.50 and <200) then State=1 if
(PatientDiffAve*2.gtoreq.30 and <50) then State=2 if
(PatientDiffAve*2.gtoreq.25 and <30) then State=3 if
(PatientDiffAve*2.gtoreq.20 and <25) then State=4 if
(PatientDiffAve*2.gtoreq.8 and <20) then State=5 if
(PatientDiffAve*2.gtoreq.8) then State=6
[0031] Proceeding to the operation illustrated in FIG. 4 at 55,
progress indicator 23 displays a visual indication of the progress
of the temperature calculation based on the defined state.
Different ranges may be selected to cause progress indicator 23 to
behave differently as PatientDiffAve changes. Likewise, many
combinations or calculations based on PatientDiff1, PatientDiff2,
PatientDiff3, PatientDiffAve, PatientCountNow and PatientCountLast
may be used. Moreover, one embodiment of progress indicator 23 does
not display progress unless certain threshold conditions are met
(e.g., sensing that the probe 17 of thermometer 11 has been placed
in the patient; the thermistor reading is greater than a certain
baseline value; and/or the last several readings have all been
increasing).
[0032] In an alternative embodiment, a different intermediate
variable within the prediction algorithm may be used in manner
similar to PatientDiffAve. For example, a stability calculation may
be continuously made during the prediction algorithm similarly to
PatientDiffAve. Replacing PatientDiffAve with this stability
factor, or using it in a generally similar manner to determine
progress bar state is contemplated by the invention. For reference,
an exemplary variance stability prediction flowchart is shown in
FIGS. 5 and 6.
[0033] Referring now to FIG. 5, control unit 13 computes a moving
variance of patient temperatures. If the variance is low enough, it
reports the temperature as is (without doing any predictions). In
one embodiment, control unit 13 calculates a moving standard
deviation to determine if a temperature is stable. However, to save
execution time, taking the square root as would normally be done
for the standard deviation may be omitted. Instead, the constant
that is used for comparison is squared. Hence, the term variance
instead of standard deviation is used. Beginning at 59, control
unit 13 increment its buffer address pointer and inserts a new
reading into the buffer. Proceeding to 61, control unit 13 reads an
AutoDetection Flag and checks whether the buffer is full. If so,
control unit 13 sets a flag at 63 to indicate that the buffer is
full. If the buffer is full, as determined at 65, control unit 13
calculates the variance. If not, operations pause at 69 to remain
synchronized and the variance is set to indicate that it is
unstable or that the buffer needs more data. Then, if variance is
less than zero at 71, the variance is set to stable at 73.
[0034] Proceeding to FIG. 6, if the AutoDetection flag is set to
one at 75, the variance is less than 1600, and the temperature is
greater than or equal to 36.6.degree. C., control unit 13
determines at 77 whether the last two patient thermistor
temperature readings are within 0.87, for example, of each other.
On the other hand, if each of the three conditions is not met at
75, control unit 13 proceeds to 79. Continuing at 81, if the last
two temperature readings differ by less than 0.87, control unit 13
determines at 81 that a temperature prediction has been made. If
not, operations proceed to 79 but otherwise continue at 83 to
determine if the patient thermistor temperature readings are within
an acceptable range (e.g., 28.degree. C. to 44.degree. C.). If the
readings are outside of this range, control unit 13 considers them
to be invalid at 85; if the readings are within this range, control
unit 13 considers them to be valid predictions.
[0035] Although described primarily in the context of a predictive
thermometer, aspects of the invention also apply to a direct
measurement mode where the predictive algorithm is turned off. In
this situation, progress indicator 23 similarly shows relative
completion of stabilization of the measured temperature. The direct
measurement mode examines, for example, the convergence of actual
temperature rather than predicted temperature.
[0036] In operation, thermometer 11 indicates its status by
performing at least one temperature calculation as a function of a
detected temperature of probe. The probe 17 is adapted to be heated
by a subject for use in measuring the temperature of the subject.
By defining plurality of states, each of the states corresponding
to an amount of completion of the temperature calculation,
thermometer 11 is able to indicate progress of the temperature
calculation. In one embodiment, each of the defined states
corresponds to one or more successive operations performed in the
temperature calculation. Advantageously, thermometer 11 visually
indicates progress by displaying progress indicator 23 to a user.
The progress indicator 23 may be a progress bar having a variable
length indicative of a percentage of completion of the temperature
calculation. Likewise, progress indicator 23 may have a plurality
of segments 41 or 43 that correspond to the defined states and that
have a visual characteristic representing the amount of completion
of the temperature calculation.
[0037] It is to be understood that aspects of the present invention
may be applied to medical devices generally. For example, a
progress bar may be used in conjunction with a pump to indicate the
progress of the delivery of a desired volume of fluid.
[0038] The order of execution or performance of the methods
illustrated and described herein is not essential, unless otherwise
specified. That is, it is contemplated by the inventors that
elements of the methods may be performed in any order, unless
otherwise specified, and that the methods may include more or less
elements than those disclosed herein. For example, it is
contemplated that executing or performing a particular element
before, contemporaneously with, or after another element is within
the scope of the invention.
[0039] When introducing elements of the present invention or the
embodiments thereof, the articles "a," "an," "the," and "said" are
intended to mean that there are one or more of the elements. The
terms "comprising," "including," and "having" are intended to be
inclusive and mean that there may be additional elements other than
the listed elements.
[0040] In view of the above, it will be seen that the several
objects of the invention are achieved and other advantageous
results attained.
[0041] As various changes could be made in the above constructions
and methods without departing from the scope of embodiments of the
invention, it is intended that all matter contained in the above
description and shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
* * * * *